Acoustic signal mechanism



Mal'Ch 17, l93l M. H. BENNETT ACOUSTIC SIGNAL MECHANISM Filed Dec. 22, 1928 gwn-antw 1MM/WS Patented Mar. 17, 1931 UNITED PATENT orFiicE' Monms H. BENNETT, 0F WarnnBUnYjeoNNEemICU/r, nssisnoe, SY Masern fission `ivm-Nrs, Ifro Morro METER GAUGE a KEmzr'rraum'r fconronn'rion, yor 'Lons IsLAND CITY, NEW YORK, AfeonaonA-mion or ,DELAWARE l ACOUSTIC `SIGNAL ,M'ECHAN-ISM Application filed December 22 19284. .Serialllo 327,829.

rlhis invention rela-tes to an improvement in acoustic signal mechanism and particularly ,to such a. mechanism for -use on automobiles ,Aa-nd other vehicles.

*One object of .the present invention is to Y provide an electrically actuated signal mech anism which will 'be very efcient from the standpoint ofcurrent consumption.

Another robject is to provide a construc- G ,tion `suoh-thatthe vsound emittingdevice may be `conveniently mounted` at the front of yan .automobile While at the same time not `regluiring heavy fastening means..

`-1ith these `general objects 1n View and .some others which will be .obvious to those skilled lin :the .art from the Adescription hereinafter, .the invention ,comprises the features, ,details vof ,construction vand Combination of pants which will first be .described'in connection with the yaccompanying.ffiraxvlngs and .then .more particularly pointed out.

In the drawings,

Fig. l isa front .elevation illustrating ,the preierred embodiment ot :the invention and :the manner ,of .mounting it at .the front `of an automobile, a cross-.baratthe front of an auto- Ymobile being shown in part.

' Fig 2 isi-a side elevation of ,the .same mechanism.

Fig. 3 is a sectional .View .on .the line 3 3, Fig. i i.

' Fig. e is a detail .section on .an .enlarged scale illustrating one form `of make andbreak .de-vice which may be used. v

l `Referringuto .thedrawings and lpartioularly Fig. vl is cupe-like ,device 0f magnetic -n,lil{te-.rial h avingfan Aa rm Q-extending .from .the oup, this arm einfgxfomned, inthe present 4eizvan'iple,` by .slitting the side of the @up and .bending the jignetail outward, as will he clear from the drawing. At `theioenter of theeup 'there is ,mounted a core 3 .of magnetio'material, -nhieh ,may .be .secured tothe .cup `in .any suitable Way, as ffor `example by forming the core with ,a reducedportion atene end, inserting this through a holein the `.Wall of the cup jl, and then riveting the projecting `0f- .the @one 11.1 the amitier spa@ he- ,ti een core-and cup is la da Winding the exis 'et' wheel@ is with the principal axis of the core, that is, the planes of'theindividua'lspirals are transverse to the .said principal anis of 'the core. It will be seen :thattlie cup 1,the core andthe Winding et constitute an armor-clad electro-magnet. This electro-magnet is arranged to coaet with a suitable armature '5, which in the present instance is a disk .of :substantially the same diameter as that ofthe cup `1, this armature being of magnetic material. The .electromagnet and itsrarrmature are located Within a chamber formed by two members, each of which vconsti-,tutes a sound-producing. diaphragm. 'These diaphragm members are indicated at6 and respectively. nIn .the present example, each member comprises a disk portion 6a.,"7a, a 'fiange portion 67)., 7b, Land a sloping portion 6c, 7c connecting' the `disk portion andthe flange portion. vThe iiange -portions ofthe two members are held together Vin any vsuitable Wayso aslto makenv Waterproof joint. -In the preferred embodiment of the invention as illustrated in Fig. 3 .the flanges engage a. ring 8 and are clamped tightly to the .ring by screw-headed bolts 9 provided with nuts, these Lbolts extending vt'liimigli the flanges ,and the ring, each bolt also extending .through tabular spacing post l0, and through the Wall of a rear raising member ll. The ring 8 may be .of any suitable mate rial, but most advantageously is of compressi/ble material suchr `as rubber, suitably treated paper, or fiber, so. as to form Waterproof gasket ,between the ,flanges of the diaphragm' .members 6 7.

'The electro-magnet is secured to one oi' the diaphragm members and the armature to `the other. 1n the best embodiment of .the invention, the electro-magnet, 'being heavier than thearmature issecured' to the .rear 4diaph-.rag'm ineijnjb r 6 means ofsorews, as .indieated at 12, While the armatnre is secured ,to the iront `.difapliragn1,membei' 7, lby screws, as indicated at 13j. The rear diaphragm member 6 tivo eyelets Hand 1,5 through which pass the respective eleetriccondnctors 1,6 and 17 forming ofthe Aelectric circuit or energizing 1th?.electro-magnet. The eyeletsfity :tightly around the Yconductors Eso, that. ,there no .dilgeig of leakagearounii them. The eyelets 'Iii CIJ

may be oi suitable insulating material it desired. To the arm 2 of the magnet are secured a pair of spring contact devices, these being suitably insulated from each other and `trom the arm 2. In the present embodiment ol: the invention, one spring contact device,

indicated at 18, is longer than the other one,v

19, as will be clear from the drawing, Fig. t. Between the spring contactdevice 18 and the arm 2 is placed a block 2O of insulating material, andbctween the two contact devices 18 and 19 is placed a similar block 21 ot insu'- lating material. Screws 22 passing through holes in the Contact devices and through the insulating` blocks, are screwed into the arm 2, thereby clamliing all the parts together. rIhe screws do not. make Contact with the contact devices 18 and 19 but are suit-ably bushed where they pass througlrthe holes in said contact devices. Each contact device has a contact point, as indicated at 23 and 2l. respectively, these cooperating to close the electric circuit. The contact devices are included in a circuit with the winding l1 of the electromagnet. In the present example the longer contact device 18 is connected by a conductor 25 to one end of the winding Ll, whose other end is joined to a conductor 16 which passes through the eyelet 14 and thence through an eyelet 27 in the rear casing member 11. To the other contact device 19 is secured a conductor 17 which passes through the eyelet 15 and thence through said eyelet 27 in the rear casing member 11. The two conductors 1G and 17 when the apparatus is installed, will be connected to the terminals of a source of electricity, as tor examplea battery as indicated at- 29, Fig. 4l, the circuit incliuiling a switch device of a suitable nature, as for example the spring push button switch indicated diagrammatically at 30,14`ig. 4. The front diaphragm member, 7, carries an abutment screw 31 which is threaded through a nut soldered to the diaphragm member 7. The end ot this abutment screw 31 is arranged te encounter the projecting end ot the longer contact device 1S, when the diaphragm members move toward each other; as more fully explained hereinafter, whereby the contact points 23 and 24e are separated from each other.

.To the rear member 1l of the casing a liront member 33 is secured by any suitable means. as for example the bolts 3l passing through lhe flanges of the casing members. Thile the front member of the casing may be shaped in various ways, it is advantageous with the present construction to avoid the use oi" a horn, because this at the front of an automo- `)ile would catch the blast of air and concentrate it on the front diaphragnnwhich at the high speeds of an automobilewould give pressures on the front diaphragm such as would be likely to injure it. Y

To avoid any possibility of this, the front member 33 ot the casing in the best embodiment oit the invention is made generally conveX outward so that it has a tendency to defleet the air outward away from the center of the front member. At the same time, in order to provide for the escape of the sound waves produced by the diaphragm members suitable openings or windows are made in the front member 33 of the casing, these openings not being at the center. In the structure illustrated in the drawings, the front mem- 'bcr 33 has a raised central portion connected by a substantially cylindrical portion with a sloping or coned portion which in turn merges into first a cylindrical portion and then a lflanged portion as will be clear from the drawings. Y

The cou/ed portion is pro-vided with Vthe outlets or windows. On account oit-he stillness of the front member 33 due to its cylindrical portions the air blast due to the torward movement of the vehicle is deiected and tends Ato flow at an angle across the outlets or windows, so that to only a small extent can the air blast reach the front diaphragm member of the sound-emitting mechanism.

For the purpose of' securing the acoustic signalling` device to the front of an automobile, it is secured to a suitable holder, which in the present embodiment of the invention comprises a plate 35 held to the lower part of the casing members 11 and 33 by bolts 34 and screws 37. The plate 35 has a groove to receive the cross-bar of the automobile, this bar being indicated at X, Figs. 1 and 2. To the plate 35 is secured a cap 38 which also has a groove to receive thecross-bar. The cap 38 is bolted to the plate 35 by screwheaded bolts. as indicated at 39, and when these are drawn up tightly the holder and the signalling device carried by` it are clamped to the cross-bar X. .It is obvious that the air-blast due to the motion of the automobile will, by its pressure on the signalling device, create a torque on the cross- .bar and in time may tend to cause the holder to slip on the cross-bar To overconjie this the holder is arranged to support apressurebalancing device below the signalling device. Since a licenseftag or plate must be carried at the front ot the vehicle, it is advantageous to employ this tag as the pressure-balancing device and therefore the holder is arranged tosupport this tag below the signalling device. However, as the area of the tag may be different from the effective area of the signalling device, theholder is so arranged that the Ylever arm of the license tag may be less than that of the signalling device, wherebyY it becomes possible tomale the torque due to the wind pressurev on the license tag equal and opposite to the torque due to the wind pressure on the signalling device.v In" the present example, the holder is provided with a horizontal member 40 along its lower edge and close to the cross-` bar, this horizontal member having slots 1.o

receive bolts L Ll which hold the license-tag inA screw, 3l, engages the projecting end of the longer spring contact device, 18, and causes the contact point of the latter to be separated from the contact point of the contact device I9, thereby opening the electric circuit. The electro-magnet is thereby de-energized and the diaphragm members, by virtue of their resiliency are set in vibration. As soon as they move away from each other, the contact points close the circuit again and the operation then continues as before explained. Owing to the difference in weights between the electro-magnet and its armature the tones emitted by the two diaphragm members may be different, but the difference in tones may be modified by a proper selection of the relative thickness and resiliencies of the two diaphragm members. Also the respective weights of the armature and of the electromagnet may be varied within reasonable limits` In this way, the two tones emitted may be predetermined so as to blend in the desired way to give a satisfactory signalling note.

It will be noted that the electro-magnet and its armature constitute a highly etiicient motor device for operating the diaphragms, because there is a relatively short magnetic circuit with an air gap of low resistance.

That I claim is:

l. A hol-der for an automobile horn arranged to be secured to the front cross-bar of an automobile, said holder having means for holding an automobile license tag below the cross bar and also means for holding an electrically-controlled sound-emitting device above the cross bar, the distances, from the cross-bar, of the centers of effective windpressurc on the tag and signalling device respectively being such as to cause a substantial equalization of the two opposing torques due to said wind-pressures.

2. In combination with a signaling device adapted to be mountedl on asubstantially horizontal xture on an automobile vehicle in a position subject to wind pressures tending to create a torque on the fixture, a holder comprising a split plate secured to the signaling device above the fixture and having a portion extending below the iXture, fastening means for clamping said plate tightly around the fixture, and a bracket on the portion of said plate below the fixture to receive a pressure balancing device to overcome the torque created on the fixture by the pressure on the signaling device.

In testimony whereof, I have hereunto set my nand.

MORRIS H. BENNETT. 

